Why does my 3D model disappear after applying remesh modifier?
Remesh modifier needs mesh with volume to work properly .
Flat meshes gives blank output as it cant compute the volume and mesh with holes produce a result with the holes filled.

also try instantMesh app github link
might give usable results

If you want to remesh flat/surface/text objects then use solidify before remesh then delete the extra thickness after applying the modifiers